Architecture: Aldo Favini
Structures: Aldo Favini
Client: Consorzio Canale Navigabile Milano-Cremona-Po
Design competition: First Prize
«…The structure for this “standard bridge” for construction as a series was developed for the Consortium of the navigable Milan-Cremona-Po canal, for road bridges to cross that canal. The constraints imposed by the guidelines were as follows: a central span of 47 meters and two lateral spans of 7.5 m each. The width of the deck varied from 6 to 7.5 m, to 10.5 m. Since the bridges were to be built as a series, it seemed convenient to develop a solution of prefabricated shop components, to be transported on water or land and assembled at the sites. Putting aside the old idea of prefabrication of beams completed by a deck poured in place, the solution became one of total prefabrication, in which the basic element, the “block,” would become both the load-bearing structure and the deck.
Each bridge is thus composed of a series of prefabricated blocks placed at intervals of about 2.8 m, as wide as the deck of the finished bridge, with a length of 2.45 m. These blocks have openings in a position determined by calculations, through which to pass prestressing cables (rectilinear) that upon tensioning bond the parts together to make a monolithic whole. Other prestressing cables, with a parabolic shape, pass next to the ribs, still inside the bridge, and are guided by a concrete diaphragm with a thickness of 20 cm, also prefabricated, and placed between one block and the next. The space (7.5 m) between the prefabricated parts is completed by a pour of vibrated cement. The resulting section of the bridge is hollow-cellular with a lenticular form, with a parabolic curved thin lower vault.
The piers have an elliptical form composed of hollow prefabricated parts held in place by a pour of concrete and two prestressing cables anchored in the foundation. The braces of the piers are also prefabricated and prestressed. This is a new solution based on the desire to extend total prefabrication as much as possible to a very demanding structure, in static terms: certainly a difficult path, but one that will lead to further developments.»
From “Domus”, 429.
• Un ponte tipo da costruirsi in serie, in “Domus”, n. 429, August 1965.